import java.util.Comparator;
import java.util.Objects;
import java.util.PriorityQueue;


class CardComparator implements Comparator<Card>{
    @Override
    public int compare(Card o1, Card o2) {
        return o1.rank - o2.rank;
    }
}
/**
 * Card：扑克牌类
 * rank：数值
 * card：花色
 */
class Card {
    public int rank;
    public String suit;

    public Card(int rank, String suit) {
        this.rank = rank;
        this.suit = suit;
    }


}
public class test {
    public static void main(String[] args) {
        PriorityQueue<Card> cards = new PriorityQueue<>();
        Card c1 = new Card(9,"♣");
        Card c2 = new Card(7,"♦");
        CardComparator comparator = new CardComparator();
        System.out.println(comparator.compare(c1,c2));
    }
}
